Heat exchanger for gas turbines



Oct. 31, 1944. G. JENDRASSIK HEAT EXCHANGER FOR GAS TURBINES Filed April15, 1959 the two fluids.

Patented a. 31, 1944 FFICE HEAT EXCHANGER FOR GAS mamas GeorgeJendrasslk, Budapest, Hungary; vested in the Alien Property CustodianApplication Apr-Q15, 1939, Serial No. 268,009 In Hungary April 16, 19382 Claims.

The invention relates to s, heat exchanger for use with a gas turbineand a compressor for preliminary compression of the working fluid. Inplants oi. this character only moderate temperatures (500 to 600 deg.centigrade) are permissible, and it is therefore desirable to recoverthe heat of the spent gases from the turbine for use in heating thefresh working fluid from the compressor, in order to obtaingreater'efiiciency. In this way the temperature of the fresh fluid ofhigher pressure leaving the heat exchanger to enter the turbine shouldapproximate as far as possible the temperature of the spent gas of lowerpressure leaving the turbine. This invention is designed to provide aheat exchanger for this purpose, which comprises series of metal sheetsforming the flow spaces for the heat transmitting fluid from the turbineand the heat absorbing fluid from the compressor. To increase the heattransfer between these fluids, they are passed through the flow spacesin mutually opposite directions. As will fully appear from the followingdetailed description of the structure of the heat exchanger, thiscounterfiow is provided by two series of passages for the heattransmitting and heat absorbing fluids respectively. By the peculiarform 01 the sheets, the passages of one of these series, for the heatabsorbing fluid which is under higher pressure from the compressor, areformed by the spaces enclosed by the sheets, and the passages of theother series, for the heat transmitting fluid which is under lowerpressure from the turbine, are formed by the spaces between sheets.These latter passages are closed along the sides of the sheets by linerbands which are provided with series of gaps or interruptions. Theadvantage of these gaps is that they reduce or eliminate the loss ofheat caused by conduction by the liner bands from the hotter end to thecooler end of the heat exchanger. Suitable means are provided for entryand exit ports i'orthe passages, to provide the eounterilow-oi' thefluids.

In the drawing: I

Fig. 1 is a horizontal section or the heat exchanger illustrating thedirections of flow oi the cotmtercurrents of the heat absorbing and theheat transmitting fluids.

Fig. 2 is an enlarged perspective view of a seriesof sheets, the sheetsbeing broken away to show their relation to io'rmthe alternatepassagestor Pig. 8 is a fragmentary side elevation oi'the series 01'sheets shown in Pig. 2.

mulls:

transverse vertical section through alerlocoitheshoets. 1

E at the right of I sage M is closed at portion B--3.

disposed the substantially hexagonal sheets arranged in a series to formthe passages for the fluids. For purpose oi illustration, there areshown in Fig. 2 three sheets A, B and C. All the sheets are formed withparallel sides S andconverging ends E with a tongue Textending outwardlyfrom each end. The sheet A has two down-pressed ribs A-i symmetricallydisposed on either side of the longitudinal axis, parallel to the sidesS and with end portions reversely turned toward the edges of theconverging ends E of the sheet. The sheet B has a peripheral flange 3-4,a peripheral shoulder 3-2 and a raised The sheet B has anupwardlypressed rib, B-4 disposed on the longitudinal axis with endportions reversely turned toward the edges of the converging ends E ofthe sheet. The sheet C is identical with the sheet A.. As illustrated inFig. 2, sheet B is placed upon sheet A and sheet C is placed upon sheetB. By reason or the shoulder B-I forming the raised portion 18-3 of theplate B, there is provided the Dessage M between sheets A and B, and byreason -01 the rib 3-4 of sheet B and menses-I or sheetC, spacing apartthe C (Fig. 4)..

the sheets B and C resting upon continuity of the bands L inbeioreexplained. i a

In order to provide for the oounterflow of the fluids through thepassages M and N r'espectivelm; it is necessary to provide the passageswith inlet" and outlet ports at their respective ends, and these willnow bedescribed. As clearly illustrated in Fig. 2, the pass M has anentry Port P--l at the near edge of the end E at the left oi the-figure,which is provided by interrupting the flange B-.l and shoulder 3-2 ofthe sheet B, the exit port P--2 for passage M being providedby a similararrangement on the tar edge of the end'E at the right of the figure.Since the flange B are not interrupted at the near edge of the end thefigure and correspondingly, or the end Eat the left, the pasthoseportions.

Directly above the entry sage N. there is provided a suitable closureblock 0 between the sheets B and C to close the posat the far edgesheets B and C, ther'i; is formed the passage N between the sheets 13and} 3-] and shoulder B -Z of sheet port P-l of the 3293- sage N,suitable packing O-l such as solder being provided at the outer ends ofblock between it and the flange B-l of sheet B and the adjacent linerband L. A similar closure 0' is provided above the exit port P--2'.Since the closures O and O' are applied to the passage N only at theseportions directly above the ports P-i and P-Z, the passages N have entryand exit p0rtsP3 and P-fl respectively directly above the closed endportions of the passages M.

As illustrated in Fig. 1, the assembled sheets A, B and C haveappliedthereto, at each end of the assembly, a casing 2 having a wall 2-aapplied to one side of the tongues T of the sheets A, B

and C and another wall 2-47 extending to and applied against the ends ofthe liner bandsL, to communicate with the ports P-- i and P-2respectively, of the passages M. The relation of the assembled sheets A,B and C and the casings 2 is such that only the passages M communicatewith the casings 2 and the passages N are so closed as not tocommunicate with the casings 2.

An entry pipe 3 passed through the wall l connects with one casing 2 andan exit pipe 4 passed through the wall 9 connects with the other casing.The pipes 23 and #3 supply the heat absorbing fluid to the passages M,through their entry and exit ports P-i and P--2.

Anentry pipe 5 passes through the wall t adjacent the pipe 6 and an exitpipe 6 passes through the wall 8 adjacent the pipe 8. The pipes 5 and 6,communicating with the interior of the heat exchanger, supply the heattransmitting fluid to the passages N through their entry and exit portsP-8 and P-d.

What is claimed is:

1. A heat exchanger for high pressure fluids comprising a plurality ofsubstantially parallel spaced sheets of a general hexagonal shape, meansto close the peripheries of said sheets to form spaces therebetween forpassage of heat exchange fluid, said means being interrupted alternatelyat each of the four edges of the hexagonal sheets in opposedlongitudinal relation to form entry and exit ports for alternate spacesbetween the sheets, said means including hands between the margins ofpairs of said sheets and extending longitudinally of said sheets, saidlongitudinally extending bands being interrupted at intervals todecrease heat transfer from one end to the other, thereof.

2. A heat exchanger for high pressure fluids comprising a plurality ofsubstantially parallel spaced sheets of a general hexagonal shape, meansto close the peripheries of said sheets to form spaces therebetween forpassage of heat exchange fluid, said means being interrupted alternatelyat each of the four edges of the hexag onal sheets in opposedlongitudinal relation to form entry and exit ports for alternate spacesbetween the sheets, said means including bands be=- tween the margins ofpairs of said sheets and extending longitudinally of said sheets and inparallelism to the path oi flow of said heat exchange fluid, saidlongitudinally extending bands being interrupted at intervalstoclecrease heat transfer from one end to the other thereof.

GEORGE JENDRASSIK.

